Re: Zero from bench is different to zero from prone?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Graham</div><div class="ubbcode-body">Three Mils down and three Mils right is too much of a shift to be a positional zero issue.</div></div>
I agree and disagree. I agree because it does seem excessive from bench to prone (but not standing/sling to prone/bipod). I disagree because I have a very complete dope book from when I was still an SDM student; I was later one of the instructors. We made all the students keep one of these, marking each and every shot. They learned NM shooting first, with irons and sling, to 600m. Using a plain Jane M4, which isn't the most accurate weapon to begin with, they have an acceptable 4MOA differential between them considering the ammo, M855. Now if most issue weapons are about 2MOA, why do these shooters, for instance, shoot 3MOA prone, and 5MOA standing?
Regardless of all else, the answer is always the same. Consistency in position.
It is very common for a shooter to have completely different zeroes from one position to another (I find it is most noticeable between standing/sling and prone/bipod/sandbag). I noticed that this is very noticeable with a non-FF barrel, like a standard issue M4 (a heavy barrel and KAC FF handguard cut the error roughly in half for my particular setup, and the groups were tighter, more consistent). This is because of the different stresses that are put on the barrel in the different positions --and with a shooting sling, that can be some pretty severe stress.
But it isn't just the gear. In fact, you can learn a 4MOA rifle on target just as you would a .5MOA. YOUR job is to cut the error down, analyze what is left, and work around that. Regardless of the gear. Your position is part of it that, most of that. It isn't fully to blame either though --we just exert different forces in different positions. So you drive for consistency.
What you want to achieve is the SAME position IN those positions --ie, your seated position is always the same seated, your prone is always the same prone, etc.
You want the cheek weld as close to the same as you can get it everytime, as this affects your line of sight through the sights themselves (and is more pronounced with an optic). What I did as a kid, was to tape a dime on my stock. You'll know when you get it right, because Roosevelt's impression will be in perfect alignment on your face.
The army (and marines I think) teach nose to charging handle. I think they do so mostly because that is a fixed part that won't change from person to person; the dime trick does the same thing. The point is still to line the eye up behind the sights in the same spot each time.
I, for one, saw a lot in the nose to charging handle scheme and switched to that. Haven't looked back. With other rifles, I may still use the dime until it becomes natural.
But like was mentioned early on here, you do not, in fact, have a zero issue until you have some documentation. Calling and marking each shot is invaluable. But noticing this and asking the right question, like you did, is the first step.
A good dope book will also uncover a lot of other errors and give you some idea of how you are doing in each position, at each range. Keep track of weather, etc. too. The better your notes are, the more useful that book will be. You may need to work on some positions more than others, or the same ones at different ranges. Regardless of what you do, you ALWAYS focus on SAME, SAME, SAME. Consistency is key.
If you are new to this and want to cut through the bullshit and get to the meat right now, I'd highly recommend you go learn NM shooting and shoot some matches. Not only are they fun, but that SINGLULAR prospect made me a much better shooter. I thought I was good until I mastered that. It is why we used it to train SDM's. NM makes you a good shooter, plain and simple, and good shooters make better SDM's and snipers than shitty ones do.
